Electrical connector for power cable

ABSTRACT

An electrical connector for a power cable having a lead assembly which forms electrical connections between wires in the cable and contacts to one side of the cable.

FIELD OF THE INVENTION

The invention relates to an electrical connector on a power cable for forming AC power connections with a DC-to-AC inverter on a solar panel.

THE INVENTION

Photovoltaic solar panels generate electrical power. Large numbers of panels are arranged in fields or arrays. A power cable connects the outputs of the panels to a power grid.

Solar panels generate DC electrical power. A DC-to-AC inverter is mounted on each panel to convert the DC power output to alternating current. An electrical connector assembly forms three electrical connections between AC output contacts in the inverter and the wires of a three-wire AC power cable connected to the power grid.

The assembly includes a low-profile cable electrical connector which removably engages a connector socket on the inverter. The cable connector includes an interior module forming electrical connections with the three wires in the cable and connecting the wires to three spaced contact pins extending along one side of the cable connector in three contact barrels spaced along the cable. The contact barrels surround the contact pins and are extended into three spaced recesses in the inverter with the contact pins engaging output terminals in the inverter. Low level latches on either end of the cable connector extend into latch recesses in the inverter in either end of a connector socket to form removable latch connections holding the cable connector on the socket. The latch members are located below the barrels to reduce the height of the cable connector.

The latch members are integrally molded in the cable connector and include rigid x-shaped supports and reverse-bend latch arms which engage latch surfaces on the socket. A rib on each support prevents over-flexing of the support latch arm.

The cable connector includes an integral lead assembly with metal leads attached to the cable wires and extending across the wires to the contact pins. The power transmitting wires in the cable extend along the length of the cable and are not deformed laterally to form connections with the contact pins spaced along the length of the cable connector.

The three pin contacts on the cable connector are spaced along the length of the cable and may be joined to the connector socket on the inverter in either of two positions, in order to facilitate routing of the cable according to the locations of the inverters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a number of solar panels in an array of panels with DC-to-AC inverters on the panels connected to an AC power cable;

FIG. 2 is a perspective view of an electrical connector assembly and a release tool;

FIG. 3 is a front perspective view of a cable connector;

FIG. 4 is a perspective view of a connector socket on an inverter;

FIG. 5 is a perspective view of the release tool;

FIG. 6 is a vertical sectional view taken through the connector socket;

FIG. 7 is a horizontal sectional view taken through an interface between a right-angle header and the inverter body;

FIG. 8 is a top view of the electrical connector assembly, partially broken away;

FIG. 9 is a horizontal sectional view through the assembly illustrating latched engagement of the socket and cable connector;

FIG. 10 is an exploded view of the cable connector;

FIG. 11 is a top view of a lead frame assembly on the power cable;

FIG. 12 is a bottom view of the lead frame assembly on the power cable;

FIG. 13 is a partial bottom perspective view of the lead frame assembly;

FIGS. 14, 15 and 16 are rear perspective views of the cable connector illustrating assembly;

FIG. 17 is a sectional view taken along line 17-17 of FIG. 14; and

FIG. 18 is a vertical sectional view taken along line 18-18 of FIG. 16.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Electrical connector assemblies 8 are spaced along three-wire AC power cable 12 shown in FIG. 1. The cable transmits AC current generated by photovoltaic solar panels 16 to an AC power grid. Each assembly 8 includes an electrical connector 10 on cable 12 and a connector socket, sometimes also referred to as an electrical connector, 52 forming part of an AC-to-DC inverter 14. Inverters 14 are mounted on panels 16. Each assembly 8 forms an electrical connection between output contacts of the inverter 14 mounted on the solar panel 16 and three wires in the cable. The output contacts are housed in connector socket 52 on the inverter. DC power generated by panels 16 is converted to three-phase AC power by inverters 14, and flows from sockets 52 in connectors 10 to the wires in cable 12 and through the cable to a distribution point on a power grid.

Cable connector 10 includes an elongate, hollow plastic body or housing 18 having an open back and cover 20 closing the open back of the housing. Housing 18 has a flat front face 22 away from cover 20. Rectangular projection 24 extends out from face 22 to forward surface 26. Three hollow contact barrels 28 extend outwardly from and are spaced along the length of forward surface 26. A three-rib resilient sealing gasket 30 surrounds each barrel 28.

Projection 24 is located on the center of face 22. One-piece plastic latch members 32 extend out from face 22 to either side of projection 24 end walls 40. Each latch member 32 includes an x-shaped arm support 34 extending outwardly from face 22 to a rounded end 36 and a straight and flexible latch arm 38. The arm 38 extends inwardly from end 36 at an angle toward face 22 and adjacent wall 40. Latch surface 42 is located on the inner, free end of arm 38 adjacent face 22. Latch members 32 are integrally molded parts of plastic housing 18.

Support 34 includes flat rib 46 extending from face 22 to end 36. Rib 46 is the same width as arm 38 and parallels wall 40. Perpendicular rib 48 extends from face 22 to end 36 at the center of rib 46 on the side of the rib 46 away from arm 38. Rib 48 has an inwardly sloped guide surface 44. Narrow perpendicular rib 50 extends from face 22 approximately half way to end 36 at the center of rib 46 on the side of the rib facing arm 38. Ribs 46, 48 and 50 form a strong, cross-shaped support for arm 38. Rib 50 permits limited inward flexing of arm 38 during latching engagement of connector 10 with socket 52 on inverter 14 and during unlatching. Rib 50 prevents over-flexing and injury to arm 38.

As shown in FIG. 4, connector socket 52 is part of inverter and has an elongate, rectangular plastic body 54 with an elongate, rectangular central recess 56 and like end latch recesses 58. Three cylindrical openings 60 open into the bottom of recess 56 to receive contact barrels 28 when connector 10 and socket 52 are engaged. Guide ribs 62 on the interior walls of central recess 56 to either side of each opening 60 guide the barrels into the openings.

As illustrated in FIG. 6, inverter 14 includes an internal circuit board 80. Right-angle header 82 is mounted on the edge of circuit board 80 at socket 52. Three right-angle contacts 83 in header 82 are connected to power output leads on board 80 and have output contacts 84 for engaging contact pins on assembly 8. Each contact 84 is located centrally in an opening 60.

FIG. 7 is a horizontal sectional view through an interface between vertical front surface 170 of right-angle header 82 and a vertical inner surface 172 on the inverter body at socket 52. Vertical triangular rib 174 on the inverter body extends inwardly of surface 172 and fits snuggly into vertical groove 176 in header 82.

During assembly of socket 52, the right-angle header is rigidly mounted on circuit board 80, and the header and board are loosely positioned in the interior of inverter 14. Surface 170 on the header is then brought into engagement with inverter surface 172 with rib 174 fitted in groove 176. The engagement between the rib and groove laterally positions the header on the connector socket so that output contacts 84 are properly located in the centers of openings 60, in position to engage the pin contacts when cable connector 10 is inserted into the inverter. After the right-angle header is properly positioned laterally in the connector socket, circuit board 80 is secured to the inverter body, typically by screw fasteners, to maintain proper positioning of the board and right-angle header. The rib and groove are located between two barrels 28.

As shown in FIG. 9, latch recesses 58 extend deeper into socket 52 than central recess 56 in order to accommodate latch members 32. The latch members 32 extend outwardly from face 22 further than the height of projection 24. Location of latch member 32 on face 22 below forward surface 26 locates the ends of barrels 28 and latch members 32 at about the same distance above face 22. The latch members 32 have a height sufficient to permit flexing of arms 38. The increased height of the latch members 32 permitted by recessed face 22 increases the length and flexibility of arms 38 and reduces the depth of recesses 58.

Walls 64 separate central recess 56 from latch recesses 58. The outer ends of walls 64 include angled projections 65 and stop surfaces 66 extending into recesses 58 to engage latch surfaces 42 on the ends of arms 38 when connector 10 is mounted on socket 52. Latch surfaces 42 and stop surfaces 66 are perpendicular to the length of arms 38 to limit lateral movement of the arms when a withdrawal force is applied to latched connector 10. FIGS. 4, 7 and 9 illustrate latch release openings 68 formed in the top wall of socket 52. Openings 68 are over latch arms 38 when the connector 10 and socket 52 are engaged.

Latch release tool 70, shown in FIGS. 2 and 5, includes a base 72, handle 74 above the base, and two spaced cam release fingers 76 extending down from opposed ends of base 72. The fingers each have two spaced, rounded engagement surfaces 78 facing the opposed sides of base 72. The fingers extend through release openings 68 in the top of socket 52 when tool 70 is positioned over the socket 52 and lowered, as shown in FIG. 2. The surfaces 78 on one side of tool 70 engage the outer ends of latch arms 38 and flex the latch arms toward latch members 32 and out of engagement with stop surfaces 66. The rounded surfaces 78 smoothly cam the arms 38 out of engagement with surfaces 66 without injury to the arms. The two surfaces 78 on each finger 76 permit the tool to be inserted in the socket in either of two orientations to unlatch connector 10.

During insertion of fingers 76 into openings 68 to release arms 38 from the latched positions, the fingers 76 slide along walls 64 and are supported by the walls against deflection during outward camming of arms 38.

As illustrated in FIG. 10, electrical connector 10 includes plastic housing 18, cover 20 which closes an opening at the back of the housing, and a sealing gasket 86 for mounting between the cover and the housing and lead assembly 88 latched in the interior of the housing. End sections 90 of cable 12 are connected to assembly 88. Each section 90 includes three insulated power wires 92, 94 and 96. Cable seals 98 are mounted on sections 90 adjacent assembly 88 and are fitted into recesses 100 at the ends of the housing. Spaced alignment grooves 102 extend in along the inner surface of lower wall 104 of the housing. Latch stops 106 overlie grooves 102.

Lead assembly 88 is illustrated in FIGS. 11 and 12 and includes a generally rectangular plastic body or frame 108 having two like and spaced-apart side portions 110 and 112. Side portions 110 and 112 are joined by vertical separation walls 114 and 116 at the rear of the body and by recessed mounting strip 118 at the front of the body. Spaces or openings 120, 122 and 124 extend through body 108 between portions 110 and 112. Opening 120 is between link strip 118 and link wall 116. Opening 122 is between link wall 116 and link wall 114. Opening 124 is between link wall 114 and the adjacent edge of body 108.

Formed metal leads 126, 128 and 130 are mounted on the bottom of body 108. Central lead 126 includes contact pad 132 in opening 120, straight run 134 mounted on strip 118 and central contact pin 136 extending outwardly from body 108.

Side lead 128 includes contact pad 138 in opening 122, lowered L-shaped run 140 mounted on side portion 112 and outwardly extending contact pin 142 to one side of contact pin 136.

Side lead 130 includes contact pad 144 in opening 124, lowered L-shaped run 146 mounted on portion 110 and outwardly extending contact pin 148 located at the same level and in alignment with contact pins 136 and 142 on the other side of contact pin 136.

Contact pads 132, 138 and 144 have contact surfaces which face upwardly in their respective openings for forming electrical connections with the conductor ends 158 of wires 92, 94 and 96 on the top of body 108, as shown in FIG. 11.

The metal leads 126, 128 and 130 are secured to body 108 by snap engagement with pins 131 extending from the body, as illustrated in FIG. 12, or may be molded in the body, as desired.

As illustrated in FIG. 12, the L-shaped runs 140 and 146 are located at a level to one side of or below the contact pins 142 and 148 and pads 138 and 144. This offset of the runs permits the runs to cross over wires 92 and 94 while the pads and pins are at the same level.

A pair of spaced mounting projections 150 extend outwardly from the opposed edges of portions 110 and 112 at the bottom of the assembly. Latch arms 152 extend outwardly from portions 110 and 112 above projections 150. See FIGS. 12, 13, 14 and 17.

FIG. 11 illustrates the top of lead assembly 88. Cable seals 98 are placed on cable ends 90. Insulation on the inner ends of the wires 92, 94 and 96 is stripped away, exposing conductor ends 158. The ends of wires 92, 94 and 96 in the two adjacent end sections 90 of cable 12 are positioned on the top of body 108 away from leads 126, 128 and 130. Two wire holders 154 hold the ends of the wires in place on portions 110 and 112. Each wire holder 154 includes a recess for each wire. The wire holders are latched onto portions 110 and 112 by four latch fingers 156, shown in FIG. 12 to hold the wires in place on assembly 88. The fingers extend through holes in portions 110, 112 and latch against the lower surfaces of the portions.

The conductor end 158 of each wire is welded to the upwardly facing contact surface of a contact pad to form an electrical connection between the wire and pad. The conductor ends for wires 92 are welded to pad 132. The conductor ends for wires 94 are welded to pad 138. The conductor ends for wires 96 are welded to pad 144. The wire ends and pads are positioned in openings 120, 122 and 124 away from plastic body 108 to provide access for tooling to make the welds without injury to the plastic.

The wires are preferably welded to the contact pads. Other types of metallurgical bonds may be used, including soldering. Separation walls 114 and 116 maintain electrical isolation between the wires and pads. Wire holders 154 secure the wires to body 108. The holders may be attached after bonding the conductor ends to the pads.

Contact pins 136, 142 and 148 are spaced to one side of and along the length of cable 12. Flat central lead 126 extends laterally from the cable directly from pad 132 to contact pin 136.

Lead 128 extends from pad 138 a distance along wire 94, crosses wires 94 and 92 and joins contact pin 142. The L-shaped portion of lead 128 is located on the side of body 108 away from the wires.

Lead 130 extends from pad 144 a distance along wire 96, crosses wires 96, 94 and 92 and joins contact pin 148. The L-shaped portion of lead 130 is located on the side of body 108 away from the wires.

Connector 10 is assembled by positioning assembly 88 and wire ends 90 adjacent the open back of housing 18 as shown in FIG. 10 and then moving the assembly 88 and wire ends 90 into the housing to extend the pins 136, 142 and 148 through close-fit openings in body 18 and into the interior recesses 162 in contact barrels 28 as shown in FIG. 3. Mounting projections 150 extend into alignment grooves 102 to properly position the frame assembly 88 in housing 18. When the housing is fully inserted, as shown in FIG. 17, latch arms 152 snap behind latch stops 106 to hold the assembly in the housing. The entire assembly is fitted in the housing. Cable seals 98 are fitted in recesses 100 at the ends of the housing.

After the assembly and cable seals have been fitted in housing 18, liquid urethane potting material is flowed into the interior of the housing to surround the assembly and wires in the housing. Sealing gasket 86 is placed over the open end of the filled housing and cover 20 is latched onto the housing with edge latches 164 on the interior surfaces of the top and bottom walls of the cover engaging latch projections 166 on the top and bottom of the housing. Screws 168 secure the corners of the cover to the housing. The gasket 86 overlies the flat sides of cable seals 98 to form a flow-tight seal when the cover is latched and screwed onto the housing. See FIG. 4.

A number of electrical connectors 10 are mounted on cable at appropriate locations for forming electrical connections with panels 16 in a solar panel field or array. Each connector is mounted on the connector socket 52 for the DC-to-AC inverter on the panel by aligning the connector 10 with socket 52 and then extending the three barrels 28 into central recess 56 in alignment with cylindrical openings 60. The guide ribs 62 center the barrels vertically in the openings and position the barrels vertically for extension into the openings. Guide surfaces 44 help align connector 10 horizontally.

The contact pins 136, 142 and 148 in the barrels 28 extend into and form electrical connections with the three output contacts 84 in openings 60 in socket 52. Sealing gaskets 30 are compressed as the barrels move into openings 60 and form environmental seals for preventing moisture or gases from flowing into the interior of inverter 14. Latch recesses 58 do not open into the interior of the inverter. Contacts 84 form electrical connections with the contact pins to connect the three-phase AC output from inverter 14 to the three wires in cable 12.

The three spaced barrels 28 with surrounding three rib sealing gaskets 30 form tight, high-friction connections between connector 10 and socket 52. These connections and latches 32 hold the socket and body together. The equally spaced-apart barrels 28 and openings 60 permit connector 10 to be plugged into socket 52 in a first position or in a second position rotating 180° from the first position. Each latch member 32 may be latched into either latch recess 58.

Movement of connector 10 into socket 52 extends latch members 32 into latch recesses 58. The rounded ends of the members facilitate piloting into the recesses. As the members are moved into the recesses, latch arms 38 engage projections 65 on the outer ends of walls 64 and are flexed inwardly, away from walls 64 as members 32 are moved into recesses 58. The distance between the narrow rib and the projection at the mouth of each recess is greater than the thickness of the latch finger. This permits insertion of the latches into the latch recesses. Ribs 50 prevent over-flexing. When socket 52 is fully inserted into connector 10, as illustrated in FIG. 9, latch arms 38 pass projections 65 and snap back against surfaces 66 on the projections to latch the connector to the socket.

In order to unlatch socket 52 from connector 10, tool 70 is positioned above the socket with release fingers 76 above openings 68. The tool is then moved down to extend the fingers into openings 68 so that the surfaces 78 facing the connector 10 engage arms 38 and flex the arms toward ribs 50 and out of engagement with latch surfaces 42. With the latches disengaged, an operator may pull connector 10 from socket 52. During disengagement, the ends of arms 38 slide along the fingers and out from recesses 58. The sides of the fingers away from the walls 64 are inside projections 65. Walls 64 support release fingers 76 during unlatching. 

1. A lead assembly for a cable connector, the assembly comprising an insulating body having a top and a bottom, and opposed and spaced apart side portions extending away from a body side; first and second metal leads on the bottom of the body, the first metal lead having a first pad in an opening in the body between the body portions, a first contact at the side of the body and a first run extending between the first pad and the first contact; the second metal lead having a second pad in an opening in the body between the body portions, a second contact at such side of the body and a second run between the second pad and the second contact; each pad having a contact surface facing the top of the body; a wire holder on the top of one body portion; and two wires in the wire holder, each wire including a conductor end in electrical connection with a pad at a contact surface, wherein said conductor ends are spaced away from the side of the body and the contacts are spaced along the side of the body.
 2. The lead assembly as in claim 1 wherein the first run extends along one side portion and is at a level below the first and second contacts.
 3. The lead assembly as in claim 2 wherein said first run extends past the second pad, and said contacts and said pads are the same level.
 4. The lead assembly as in claim 1 including two openings in the body between the side portions, one pad in each opening.
 5. The lead assembly as in claim 4 wherein said insulating body includes a separation wall between said openings.
 6. The lead assembly as in claim 1 including three openings in the body between the side portions, a third metal contact on the body having a third pad, a third contact adjacent said contacts at said side and a third run extending between the third pad and the third contact, said contacts at a level; and said pads at a level, and an additional wire in the wire holder, the additional wire comprising a conductor end between the side portions in electrical connection with the third pad.
 7. The lead assembly as in claim 6 wherein two of said runs are located below said pads.
 8. The lead assembly as in claim 1 wherein said the body includes a mounting projection, and a latch arm on each side portion located away from said openings.
 9. The lead assembly as in claim 1 wherein the wire holder includes two latch fingers engaging a side portion to either side of a lead run.
 10. The lead assembly as in claim 1, wherein one run is L-shaped.
 11. A lead assembly for a connector, the lead assembly comprising an insulating body and first and second metal leads, the insulating body having a top and a bottom and two spaced side portions with openings extending through the body between the side portions; each metal lead including a central run, a pad at one end of the central run located in one opening, and a contact at the other end of the central run located at one side of the body, the central run of one lead extending along a side portion on the bottom of the body and past the pad on the other lead, both said contact portions at the same side of the body, wherein the pads are positioned adjacent each other between the side portions, each pad including a contact surface facing the top of the insulating body for establishing electrical connections with wire conductors on the top of the insulating body.
 12. A lead assembly as in claim 11 wherein said contacts and said pads are at the same level and one run is located at a level below such level and extends along a side portion and past the pad on the other contact.
 13. A lead assembly as in claim 12 wherein said one run is generally L-shaped.
 14. A lead assembly as in claim 13 including a third metal lead, the third metal lead including a third central run, a third pad at one end of the third central run located in an opening, and a contact at the other end of the central run located at said one side of the body adjacent said first and second contacts, said contacts spaced along said side of the body.
 15. The lead assembly as in claim 14 wherein each central run is either straight or L-shaped.
 16. The lead assembly as in claim 15 including a wire holder on the top of each side portion, three wires in each holder, each wire including a conductor end bonded to a pad.
 17. The lead assembly as in claim 16 wherein each wire holder includes a latch finger engaging the adjacent side portion.
 18. The lead assembly as in claim 17 wherein each side portion includes a latch for mounting the lead assembly in a connector body.
 19. A lead assembly for a connector, the lead assembly comprising an insulating body having a top, a bottom, a body side, and two side portions extending away from the body side and two pad openings extending through the body between said side portions; and first and second metal contacts on the bottom of the body, each metal contact including a pad in an opening, a contact on said body side and a run extending between the pad and the contact, each pad having a contact surface facing the top of the body, said contacts spaced along said body side, said openings spaced away from the body side; wherein said contacts engage an electrical connector adjacent said body side and said pads are spaced apart across the body for forming electrical connections with wires on the top of the body extending generally parallel to the side.
 20. The lead assembly as in claim 19 including a third opening and a third metal contact having a pad in a pad opening, a contact on said body side and a third run extending between such pad and such contact, wherein two runs are generally L-shaped and one run is generally straight. 